Electric arc extinguishing apparatus



N. F. ARONE ErAL 2,443,017

ELECTRIC ARC EXTINGUISHING APPARATUS `une 8, 1948.

Filed July4 18, 1944 2 Sheets-Sheet l Inventors Eugene W. Boehme,

Nicholas FT Arone,

N. F. ARONE ETAL ELECTRIC ARC EXTINGUISHING APPARATUS June 8, 194s.

a m mmm h @BAMw 2 vnl ,mmww .m e u h EN T Filed July 1a, 1944 Patented'June 8, 1948 UNITED sTATEs PATENT OFFICE ELECTRIC ARC EXTINGUISHINGAPPARATUS Nicholas F. Arone, Upper Darby, and vEugene W. Boehne, DrexelHill, Pa., asslgnors to General Electric Company, a corporation of NewYork Application July 18, 1944, Serial No. 545,460

(Cl. 20o-147) 16 Claims.

scription proceeds and the features of novelty which characterize ourinvention will be pointed out with particularity in the claims annexedto and forming a part of this specification.

For a better understanding of our invention reference may be had to theaccompanying drawings in which Fig. 1 isa sectional view of an electriccircuit interrupting device embodying our invention;.Fig. 2 is asectional view taken along the line 2 2 of Fig. 1 looking in thedirection of the arrows but showing a complete device; Fig. 3 is afragmentary view similar to Fig. 1 of a modification oi' our invention;Fig. 4 is a sectional view taken along the line 4 4 of Fig. 3 looking inthe direction of the arrows but showing a complete device; Fig. 5 is afragmentary view similar to Fig. 3 of another modification of ourinvention; Fig. 6 is a partial perspective view of another modiilcationof our invention; Fig. 7 is a sectional view taken on line I--l of` Fig.6; Figs. 8 and 9 are partial perspective views of other modiilcations ofour invention; Fig. 10 is a sectional view taken on line IU-IIl'of Fig.9, and Fig. 11 is a partial perspective view of still anothermodiflcation of our invention.

Referring now to Figs. 1 and 2 of the drawing, we have disclosed ourinvention yas applied to an air circuit breaker comprising a pluralityof relatively movable contacts. As' illustrated in the drawing, thesecontacts comprise a pair of stationary current carrying contacts I and 2connected to line terminals 3 and 4, respectively. Stationary contacts Iand 2 are adapted to be bridged by movable current carrying contact 5mounted on a movable operating rod 6. Suitable springs 1 may be providedbetween rod 6 and movable current carrying contact or bridging member 5to give the desired contact wipe. Preferably the circuit breaker is alsoprovided with arcing contacts comprising movable arcing contact 3adapted to engage stationary arcing contacts 9 and I0. Preferably arcingcontact 8 is formed of Van arc resistant material and is bifurcated asshown at II in order to provide a spring action with reference toengagement with stationary arcing contacts 9 and I0.' between whichmovable arcing contact 3 is wedged.

The relatively movable contacts described above are associated with anarc extinguishing chamber embodying our invention and generallyindicated at I2 which comprises a pair of arc runner enclosures in theform of expulsion tubes I3 and I4 preferably formed, or at least linedwith an insulating material of a type which evolves gas when subjectedto the heat of an electric arc. In the embodiment of our invention shownin Figs. 1 and 2 the arc runner enclosures comprising expulsion tubes I3and I4 are arranged closely adjacent each other in parallelrelationship. Each of the expulsion tubes I3 is provided with a narrow,longitudinally extending slot I6. The sloteln one tube, such as I3 forexample. is arranged to face the slot in the tube I4 and besubstantially coplanar therewith, so as to deilne a narrow arcextinguishing passageway I6 between expulsion tubes I3 and I4. As shown,the width of this longitudinally enclosed passageway is materially lessthan the width of the opening in the tubes I3 and I4.` This passagewayis also-bounded by insulating material which may be of the gas evolvingtype and which may either be integrally formed with expulsion tubes I3and I4, as is illustrated in Fig. 2, or may comprise a separate insert,as is illustrated in Fig. 4. Preferably the arcing contact Il extendsinto the lower end of the passageway I6 and the stationary arcingcontacts 9 and III extend to the edges of the passageway I6, as isclearly indicated in Figs. 1 and 2.

In order to accelerate the arc drawn at the lower end 0i' the passagewayI6 into arc runner enclosures comprising expulsion tubes I3 and I4, weprovide in each expulsion tube I 3 and I4 an arc runner II which may beintegrally formed with its associated stationary current carryingcontact I or 2 and stationary arcing contact 9 or I0. Arc runner I1extends longitudinally o f tubes I3 and I4 and is preferably providedwith a tip oi arc resistant material I'I.

For the purpose of producing a magnetic field in the'arc space withinthe arc runner enclosures comprising expulsion tubes I3 and I4 forassisting electromagnetically the rapid movement upward of the arc inthe expulsion tubes, we preferably provide a `tube of magnetic materialI8 surrounding each of the expulsion tubes I3 and I4. As shown, theexpulsion tubes I3 and I4 are cylindrical and alsothe tubes I8 arecylindrical and concentric with the expulsion tubes. The tubes I8 beingof magnetic material also greatly increase the bursting strength of thearc extinguishing chamber I2 of our invention. It will be obvious thatthey must also be provided with slots corresponding to the slots inexpulsion tubes I3 and I4 in order properly to accommodate the expulsiontubes I3 and I4 with' the passageway I6 therebetween, as is clearlyshown in Fig. 2. Also, since the magnetic tubes I8 are approximatelyc-shaped, the magnetic expulsion action is more intense in thepassageway adjacent the slots I than in the tubes I3 and I4. A suitablegas barrier Io is provided in arc extinguishing chamber I2 belowstationary arcing contacts l and I0.

In view of the detailed description included above, the operation of thecircuit breaker embodying our invention will be obvious to those skilledin the art.

Although in Figs. 1 and 2 We have specifically illustrated our inventionas being applicable to a circuit breaker having relatively separablecontacts, it is also equally applicable to circuit interrupters of thetype employing a fusible or meltable metal. Accordingly in Figs. 3 and 4I have illustrated an arc extinguished chamber which in most respects issubstantially identical with the arc extinguishing chamber I2 of Fig. 1except that it is adapted for use with a fusible element rather thanwith the relatively movable contacts of Figs. land 2. The correspondingparts of Figs. 3 and 4 are designated by the same reference numerals asin Fig. 1. A fusible element 2i is provided within passageway IB. Thisfusible element extends through openings 2l and 24 in expulsion tubes I3and I4, respectively, so that the ends thereof may be connected toterminals 3 and 4. A gas :barrier 2B of insulating material and atubular member 21 close the bottom of the arc extinguishing chamber 2liexcept for a central opening leading to passageway I0.

In Fig. 5 we have illustrated our invention as being applicable to alightning arrester, and arc extinguishing chamber 28 is substantiallyidentical with the arc extinguishing chamber 20 of Fig. 3, except thatthe fusible element 2i is replaced by a pair of spaced electrodes 29 and30 electrically connected to arc runner I1. The corresponding parts ofFig. 5 are designated by the same reference numerals as in Fig. 3.

We have found that an arc extinguishing chamber built in accordance withour invention will interrupt 9000 amperes at '7,250 volts when thediameter of the bore of expulsion tubes II and I4 is 1% inches with thetubes 10 inches long and the passageway I6 is 1,/8 inchby 3 inches.

From the above discussion it will be obvious that the new and improvedarc extinguishing chamber of our invention is applicable to variousforms of circuit interrupting devices, such as circuit breakers, fuses,and the like. In the arrangements described thus far the areextinguishing chambers have been substantially identical in that theycomprised a pair of spaced, parallel, vertically positioned arc runnerenclosures in the form of slotted tubes with the slots in the two tubesbeing in adjacent parallel relationship and interconnected by an arcextinguishing passageway I6 of uniform cross sectional area throughoutits height. It should be understood that our invention is not limited tothis configuration of the arc extinguishing chamber and the followingdescription is concerned with various modiflcations of arc extinguishingchambers of our invention.

Referring now to Figs. 6 and 7, we have illustrated an arc extinguishingchamber 3| comprising the vertical parallel arranged arc runnerenclosures including expulsion tubes i3 and I4 enclosed within tubes ofmagnetic material I8. The slots I5 in tubes I3 and I4 are interconnectedby a member 32 which has formed therein an arc extinguishing passageway33. The arc extinguishing passageway I3 interconnects expulsion tubes i3and I4 and since these tubes are parallel to each other the length ofthis arc extinguishing passageway isc-onstant. By length the dimensionin the direction of arc length is referred to. However, unlike thearrangements described heretofore. the arc extinguishing passageway Ilgradually converges toward the exhaust end of the arc extinguishingchamber in a manner similar to that disclosed and claimed in TraverPatent 2,314,292. granted March 16, 1943, and assigned to the sameassignee as the present application. This causes the arc drawn inpassageway I6 to be squeezed into more and more intimate contact withthe gas evolving insulating material defining arc passageway Il. Itshould be noted that arc passageway 3l narrows `so that it completelydisappears a predetermined distance from the exhaust end of the arcextinguishing chamber 3i as is clearly indicated by the dotted line 34oi Fig. 6 so that the arc products and exhaust gases must leave throughthe openings in expulsion tubes i3 and I4.

It will be understood that the arc extinguishing chambers of ourinvention may be provided with suitable mufilers or the like to furtherprevent the arc from blowing out to the open air and fromre-establishing outside the are extinguishing chamber if this should benecessary.

In Fig. 8 we have illustrated an arc extinguishing chamber I!substantially identical with the are extinguishing chamber of Fig. 1except that the arc runner enclosures comprising expulsion tubes I3 andI4 are not parallel with each other but are arranged in divergingrelationship so that the arc passageway It gradually increases in adirection parallel with the arc drawn between arc runners I1. Thecorresponding parts of Fig. 8 are designated by the same referencenumerals as in the preceding figures. The passageway I6' has been shownas having a uniform dimension in a direction perpendicular to the wallsoi' passageway I6' but it should be understood that this passagewaymight be constructed like the passageway 3s of Figs. 6 and 7.

In Figs. 9 and 10 there is disclosed an arc extinguishing chamber 36 inwhich the corresponding parts thereof are designated by the samereference numerals as in the preceding figures. In this case the arcrunner enclosures comprising expulsion tubes I3 and I4 are arranged inthe same manner as in Fig. 8 so as to diverge in a. direction toward theexhaust end of the arc extinguishing chamber. However, the arc moves ina lateral direction in its travel toward the exhaust end of the arcextinguishing chamber, rather than in a vertical direction as in thepreceding figures. The arc passageway 31 interconnecting the slots I5 inexpulsion tubes Il and I4 is serpentine in configuration in accordancewith the arrangement disclosed and claimed in the above mentioned Traverpatent. Also the passageway 31 gradually increases in length anddecreases in width from the entrance to the exhaust end of the arcextinguishing chamber, as is obvious in comparing the passageway 31 ofFig. 9 with the passageway 31 of Fig. 10 illustrating a sectional viewtaken on line Iii-II of Fig. 9. If desired, suitable exhaust openingssuch as 38 may be provided near the exhaust end of the arc extinguishingchamber or arc chute, as is clearly indicated in Fig. 9.

In Fig. 11 there is illustrated still another modification of ourinvention, in some respects similar to the arc extinguishing chamber ofFig.

- 8. The corresponding parts of Fig. 11 are desigausm? nated by the samereference'numerals asin the preceding figures. The arc e chamber IlotFlg. 11 ditiers from Fig. 8 in that the passageway lll correspondingto passageway It' is somewhat wider in a direction perpendicular to theside walls dening the passageway. Furthermore, this passageway issubdivided into a plurality of passageways by virtue of-insulatingbarriers or arc splitters 4| arranged in spaced vparallel relationshipand supported by means of bolts 42. Barriers Il are also provided with aplurality of openings I3 to interconnect `the parallel are passagewaysand permit distribution of arrangement disclosed and claimed in thecopending application of Joseph W. Seaman, Serial No. 527,913, ii-ledMarch 24, 1944, and assigned'to the same assignee as the presentapplication, now

Y Patent No. 2,429,846, issued Oct. 28, 1947.

It should be understood that when the interrupting chamber of ourinvention is used to interrupt direct currents one arc runner becomesthe cathode and the other arc runner becomes the anode. In such a caseit may be desirable tol use tubes of diierent bores and geometry toenhance the performance.

It should be understood that two or more of the arc extinguishingdevices described above should be understood that only a single tubemight be employed in accordance with our invention.

While we have shown particular embodiments of our invention, it will beunderstood oi course that we do not wish to be limited thereto sincemany modiiications may be made, and we, therefore, contemplate by theappended claims to cover all such modiiications as failA within the truespirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of theUnited States, is,

1. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent one another, means deilning a slot in eachtubeextending longitudinally thereof, said tubes being positioned withtheir slots opposed and vsubstantially coplanar, insulating means forproviding between said tubes a longitudinally enclosed passagewayinterconnecting said slots and having a width materially less than thewidth of the opening in saidtubes, means for initiating an arc in saidpassageway, and means `for lcausing the arc to travel along saidpassageway and into said expulsion tubes for rapid extinguishment of thearc.

2. An arc extinguishing chamber for an electric circuit interruptingdevice comprising an expulsion tube of insulating material, means deninga narrow slot in said tube extending longitudinally thereof, means fordrawing an arc outside of said tube, and a tubular magnetic memberaround the exterior of said expulsion tube for causing the arc to moveinto. said tube through said slot tor rapid extinguishment of the arc bythe expulsion action of the tube.

3. An are extinguishing chamber for an electric circuit interruptingdevice comprising an expulsion tube of insulating material, meansdeiining a slot in said tube extending longitudinally I thereof, meansfor establishing near one end of said tube an arc between a point withinthe the arc gases somewhat inaccordance with the tube and a pointexternal thereto. and means for causing said arc to move along said slotin a direction toward the other end of said tube comprising a tubularmagnetic member around the exterior of the tube.

4. An arc extinguishing chamber for an electric circuit interruptingdevice comprising' a cylindrical expulsion tube at least the innersurface of whichv is formed of gas evolving insulating material,meansdeflning a narrow slot in said tube extending longitudinallythereof, means for establishing near one end of said tube an are betweena point within said tube and a point external thereto, and a concentricmagnetic tube mounted exteriorly of said expulsion tube for causing thearc to move along said slot in a direction toward the other end of theexpulsion tube.

5. An arc extinguishing chamber for an electric circuit interruptingdevice comprising an expulsion tube formed of gas evolving insulatingmaterial when subjected to the heat of an electric arc, means dening anarrow slot in said tube extending longitudinally thereof, means forestablishing near one end of said tube an arc betweena point within thetube and a point external thereto, and `means comprising a tube ofmagnetic material surrounding said tube for causing the arc to movealong said slot in a direction toward the other end of the tube.

6. An arc extinguishing chamber for an electrio circuit interruptingdevice comprising an expulsion tube ot insulating material, meansdefining a narrow slot in said tube extending longitudinally thereof,means for establishing near one end of said tube an are between a pointwithin the tube and a point external thereto, an are runner in saidtube, and magnetic means for causing the arc to move along said slot ina direction toward the other end of said tube.

7. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent one another in parallel relationship, means deiining aslot in each tube extending longitudinally thereof,.said tubes beingpositioned with their slots opposed and substantially coplanar.insulating means for providing between said tubes a longitudinallyenclosed passageway of uniform cross sectional area interconnecting saidslots and having a width materially less than the width of the openingin said tubes, contact means separable in said passageway to draw an arctherein, and means for causing the arc to travel along said passagewayand into said expulsion tubes for rapid extinguishment of the arccomprising tubular magnetic members respectively embracing saidexpulsion tubes and extending longitudinally thereof.

8. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes -of insulating materialarranged adjacent one another in diverging relationship, means deilninga slot in each tube extending longitudinally thereof, said tubes beingApositioned with their slots opposed and substantially coplanar,insulating means for providing between said tubes a longitudinallyenclosed arc passageway interconnecting said slots and having a widthmaterially less than the width of the opening 'in said tubes, meansseparable in said passageway for drawing an arc therein, and magneticmeans for causing the arc to travel along said passageway and into saidexpulsion tubes for rapid extinguishment ot the arc, the arc increasingin length as it travels along said passageway.

9. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of vertically positioned expulsion tubes ofinsulating material arranged adjacent one another in parallelrelationship, means de tlning a slot in each tube extendinglongitudinally thereof, said tubes being positioned with their slotsopposed and substantially parallel, means for providing between saidtubes a longitudinally enclosed passageway interconnecting said slotsand having a width materially less than the width of the openings insaid tubes, means for drawing an arc in said passageway, and means forcausing the arc to travel upwardly in said passageway and into saidexpulsion tubes for rapid extinguishing of the arc.

10. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent one another in diverging relationship, means defininga slot in each tube extending longitudinally thereof, said tubes beingpositioned with their slots opposed and substantially coplanar, gasevolving insulating means for providing between said tubes a serpentinepassageway interconnecting said slots and having a width materially lessthan the width of the opening in said tubes, means for drawing an arc insaid passageway, and means for causing the arc to travel along saidpassageway increasing in length and coming into more and more intimateContact with said gas evolving insulating means to cause rapidextinguishment of the arc.

11. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent one another, means defining a slot in each tubeextending longitudinally thereof, said tubes being positioned with theirslots opposed and substantially coplanar, means for defining betweensaid tubes a longitudinal enclosed passageway interconnecting said slotsand having a width materially less than the width of the opening in saidtubes, means for drawing an arc in said passageway, means for causingsaid arc to travel upwardly in said passageway and into said expulsiontubes, and barriers within :aid passageway to divide and cool the arcfor rapid extinguishment thereof.

12. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent one another, means defining a slot in each tubeextending longitudinally thereof, said tubes being positioned with theirslots opposed and substantially coplanar, insulating means deningbetween said tubes a passageway interconnecting said slots, means fordrawing an arc in said passageway, and means for causing the arc totravel along said passageway and into .rzaid expulsion tubes for rapidextingulshment of the arc, said passageway being closed at the exhaustend of said arc extinguishing chamber so that the arc gases can exhaustonly through said expulsion tubes.

13. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent one another, means defining a slot in each tubeextending longitudinally thereol', said tubes being positioned withtheir slots opposed and substantially coplanar, insulating meansdefining between said tubes a passageway interconnecting said slots,said passageway being longitudinally enclosed and having a widthmaterially less than the width of the opening in said tubes, means fordrawing an arc in said passageway, means for causing the arc to travelalong said passageway and into said expulsion tubes to cause rapidextinguishment of the are, and means defining a plurality of openings inthe insulating means comprising said passageway.

14. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent each other, means defining a narrow slot in each tubeextending longitudinally thereof, said tubes being positioned with theirslots opposed and substantially coplanar, insulating means definingbetween said tubes a narrow passageway and interconnecting said slots,and means for drawing an arc in said passageway comprising an arcterminal member in each tube terminating against the wall of the tubeopposite the slot therein.

l5. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent ea-ch other, means defining a narrow slot in each tubeextending longitudinally thereof, said tubes being positioned with theirslots opposed and substantially coplanar, insulating means definingbetween said tubes a narrow passageway interconnecting said slots, means-ior drawing an arc in said passageway, and means for causing the arc totravel along said passageway and into said expulsion tubes for rapidextinguishment of the arc comprising magnetic means external to saidtubes extending longitudinally thereof and shaped to provide a moreintense magnetic blowout action at the slots than in the tubes.

16. An arc extinguishing chamber for an electric circuit interruptingdevice comprising a pair of expulsion tubes of insulating materialarranged adjacent each other, means defining a narrow slot in each tubeextending longitudinally thereof, said tubes being positioned with theirslots opposed'and substantially coplanar, insulating means definingbetween said tubes a narrow passageway interconnecting said slots, meansfor drawing an arc in said passageway comprising an arc terminal memberin each tube terminating against the wall of the tube opposite the slottherein, and means for causing the arc to travel along said passagewayand into said expulsion tubes for rapid extingulshment of the arecomprising a slotted magnetic member for each of said tubes extendinglongitudinally thereof and shaped to conform to the exterior of saidtubes whereby to provide a more intense magneticblowout action at theslots than in the tubes.

NICHOLAS F. ARONE. EUGENE W. BOEHNE.

REFERENCES CITED The following references are of record in the file'ofthis patent:

' UNITED STATES PATENTS Number

